PUMP 5355380 - Caterpillar

throttle lock allows the operator to maintain a desired engine speed without using the throttle pedal.An "ON/OFF" rocker switch is used to enable the throttle lock feature. A 300 mA driver circuit is used to turn on a lamp that indicates the active feature. Two other push button switches are used to set the engine speed at a given value. The push button switches will also resume a preset engine speed. The "Set" switch can be used interchangeably with the "Decel" input once the engine speed has been set. The "Resume" switch can be used interchangeably with the "Accel" input once the engine speed has been set.Use the throttle pedal to obtain the desired engine speed. Then, the "Set/Decel" switch can be depressed in order to set that desired speed. The operator may use the throttle pedal to increase the engine speed beyond the set point.The operator may also bump the "Resume/Accel" switch in order to increase the engine speed by 20 rpm. The operator may depress the switch which increases the engine speed at a rate of 50 rpm per second. The speed may also be reduced at a rate of 50 rpm per second by depressing the "Set/Decel" switch or 20 rpm by simply bumping the switch.The throttle lock set point is disabled when the right brake pedal is depressed. Two switch inputs are used in order to monitor the status of brake pedal. One switch input is normally open while the other switch input is normally closed. Using the switch inputs will allow diagnostics on the brake pedal switch.The previous set point may be enabled by pressing the "Resume/Accel" switch. This previous value will only exist if the right brake pedal has been used. If the throttle lock enable switch has been turned "OFF" then the previous set point is cleared from the memory. If the electronic control module has powered down then the previous set point is cleared from memory.The throttle lock desired speed set point that has been established may be viewed on the service tool status screen. This allows the mechanic to observe the set speed that is being used by the electronic control module for the throttle lock feature.